JPH031094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a foamed synthetic resin vanishing model for mold casting.

(Prior art) Molds for injection molding of plastic, rubber, etc. are cast by a full mold casting method, a ceramic casting method, etc., but the full mold casting method reduces mold manufacturing costs and significantly shortens the casting schedule. In recent years, it has attracted attention in the field of mold casting because it can be shortened.

As is well known, in the full mold casting method, a vanishing model made of foamed synthetic resin such as foamed polystyrene is buried in foundry sand (dry sand) to form a mold, and molten metal is poured into the vanishing model. This is a method of casting a casting by burning and vaporizing the model and replacing the model with molten metal.

For mold castings cast by the full mold casting method, a fluid supply path for supplying cooling water or the like is usually opened after casting to control the temperature of the mold.

Conventionally, fluid feed passages have been drilled using a radial drilling machine, a gun drill machine, or the like. An example is shown in FIGS. 1 and 2. In the figure, a plurality of through holes 12 are formed in a mold base 11, and a plurality of branch holes 14 are formed in communication with the mold forming part 13 from the through holes 12. 15 is a blind plug.

(Problem to be Solved by the Invention) However, the hole 12 forming the fluid supply path,
No. 14 requires deep hole drilling, which accounts for 20 to 30% of the machining performed on the mold, and it is necessary to remove chips from the hole when drilling, so high-pressure cutting oil is used in the drill. It is necessary to eject it from within, which requires a high-performance drilling device, which is a factor in increasing mold costs.

Additionally, due to the drilling process, the fluid feed path is necessarily straight, making it difficult to provide it at a certain distance from the molding surface. Especially when the molding surface is a curved surface, it is difficult to form it along the curved surface. It's impossible. This has become a bottleneck in controlling the temperature of the mold.

The present invention was made in view of such problems,
Provided is a vanishing model for full mold casting that eliminates the need to open holes for fluid feed passages in mold castings after casting, and can form fluid feed passages along arbitrary molding surfaces. The purpose is to

(Means for Solving the Problems) The vanishing model of the present invention, which has been made to achieve the above object, has a fluid feeding system supported by a support rod 6 inside a vanishing model body 1 made of foamed synthetic resin. The structure of the invention is that a channel forming cast-in tube 2 is provided, and the end of the support rod 6 and the end of the cast-in tube 2 are made to protrude outside the disappearing model body 1.

(Function) Since the cast-in pipe for fluid feeding is arranged inside the disappearing model body made of foamed synthetic resin, there is no need to drill a fluid feeding path in the mold casting after casting. Moreover, since the cast-in tube can be formed into an appropriate shape, a fluid feed path along the molding surface can be easily formed.

In addition, since the cast-in tube is supported by a support rod, and the end of the support rod and the end of the cast-in tube protrude outside the disappearing model body, the position of the cast-in tube within the disappearing model body is Confirmation and fine adjustment of the position can be easily performed.

(Example) Figures 1 and 2 show a vanishing model for mold casting according to an embodiment, including a vanishing model main body 1 and a plurality of fluid feed passages formed inside the main body. It is composed of a cast-in tube 2.

The disappearing model main body 1 is made of a foamed synthetic resin such as expanded polystyrene, and has a flat base 3 and a mold portion 4 formed in a bulging shape. and,
The base 3 is divided into two parts in the vertical direction, and is composed of an upper model part 1a and a lower model part 1b,
Both model parts 1a and 1b are integrally bonded at their mating surfaces. However, this adhesive integration is
This is carried out after the cast-in tube 2 is set in the upper model part 1a.

A cast-in tube storage chamber 5 is provided inside the upper model section 1a, and the storage chamber 5 is open to the lower surface of the upper model section 1a.

The storage chamber 5 contains a plurality of bottles (three in the illustrated example).
The cast-in tubes 2 are arranged side by side and housed, and each cast-in tube 2 is formed with a curved tube section shaped to follow the surface of the mold section 4. When using iron-based metal as the cast metal for the cast-in pipe 2,
Generally, steel pipes that are easy to bend are used, but stainless steel pipes are particularly suitable when corrosion resistance is considered.

The plurality of cast-in tubes 2 are fixedly supported by an appropriate number of support rods 6 so as to be in a predetermined positional relationship with each other.

The end of the support rod 6 and the end of the cast-in tube 2 protrude outward from the disappearing model body 1. Therefore, the position of the cast-in tube 2 inside the disappearing model body 1 can be confirmed and finely adjusted from the outside.
After final positioning, each protrusion is preferably fixed with self-hardening sand or the like.

In addition, the cast-in pipe storage chamber 5 in which the cast-in pipe 2 is stored
The remaining space may be left as is, but it is preferable to bury a foamed synthetic resin material of an appropriate shape.

The above-described vanishing model for mold casting is attached with a runner model and a sprue model as appropriate, then placed in a metal frame, filled with dry sand, and used for casting.

(Effects of the Invention) As explained above, the vanishing model for mold casting of the present invention has a cast-in pipe for forming a fluid feeding path supported by a support rod inside the vanishing model main body. Therefore, by subjecting the disappearing model to full mold casting, it is possible to obtain a mold in which a fluid feed path is formed at a predetermined position, and there is no need to perform drilling for a fluid feed path after casting. It is possible to reduce processing steps and processing costs.

Furthermore, since a cast-in tube of a predetermined shape can be used, the cast-in tube can be embedded along the molding surface, and a mold with good temperature control can be easily cast.

Furthermore, since the support rod supporting the cast-in tube and the end of the cast-in tube protrude outward from the disappearing model body, the position of the cast-in tube can be easily confirmed and finely adjusted.

[Brief explanation of the drawing]

1 is a front sectional view of a vanishing model for mold casting according to the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1,
FIG. 2 1 is a front cross-sectional view of a mold equipped with a conventional fluid feed path, and FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1. 1... Disappeared model body, 2... Cast-in pipe, 6...
support rod.

Claims (1)

[Claims] 1 A cast-in tube 2 for forming a fluid supply path supported by a support rod 6 is disposed inside a vanishing model body 1 made of foamed synthetic resin, and the end of the support rod 6 and the cast-in tube 2 are connected to each other. A vanishing model for mold casting equipped with a fluid feed path, the end of which protrudes outside the vanishing model main body 1.